Weeding, mulching, and cultivating implement having auger-type digging elements



March 10, 1959 L. H. STARRETT 7 WEEDING, MULCHING, AND CULTIVATING IMPLEMENT HAVING AUGER-TYPE DIGGING ELEMENTS Filed Sept. 21, 1956 2 Sheets-Sheet 1 & $3 an \9 k INVENTOR.

450M420 H. srzzee rz BY 2,876,850 MEN March 10, 1959 L. H. STARRETT WEEDING; MULCHING, AND CULTIVATING IMPLE T HAVING AUGER-TYPE DIGGING ELEMENTS Filed Sept 21, 1956 '2 Sheets-Sheet 2 II! 1 z r s Y we w mm W 5 m W 0 M v/ E W L N United States Patent WEEDING, MULCHING, AND 'CULTIVATING IM- PLEMENT HAVING AUGER-TYPE DIGGING ELEMENTS Leonard H. Starrett, Larkspur, Colo. Application September 21, 1956, Serial No. 611,167 1 Claim. (Cl. 172-42) This invention relates to ground working implements. More particularly the invention is a device usable as a weeder, soil mulcher, cultivator, etc.

Summarized briefly, the invention is a rollable frame having a motor thereon, driving a series of intermeshing gears which rotate a plurality of laterally spaced, parallel, forwardly projecting shafts on the forward ends of which spiralling digging blades are mounted. The main object is to provide an improved implement for the purposes described, and in attaining this object, I provide an arrangement in which the digging elements are assembled in first and second series, the first series having its digging elements disposed forwardly of the digging elements of the second series and rotating oppositely to the direction of rotation of the elements of the second series.

A more specific object of the invention is to provide a device of the character described which will be designed to effectively weed and mulch the ground with a minimum of power, considering the swath conditioned by the device during its forward movement and the efiiciency with which the device operates to perform its assigned functions.

Another object is to so design the digging elements as to impart thereto the characteristic of assisting in the forward movement of the device, so that the device is moved forwardly partly by the impetus given thereto by one pushing the same, and partly by the action of the digging elements themselves, thus to facilitate the operation of the device.

Another object is to form the digging elements, and have them operate, in such a manner that they will remove weeds, and loosen and mulch the soil, while throwing dirt to no more than a minimum extent.

Still anotherobject is to form the weeder in such manner that it will be light in weight considering the capacity or rating thereof in weeding and mulching operations, and will be highly maneuverable and easily handled.

Other objects will appear from the following description, the claim appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a top plan view of the implement formed according to the invention;

Figure 2 is a side elevational view thereof;

Figure 3 is a longitudinal section on line 3-3 of Figure 1;

Figure 4 is a transverse section on an enlarged scale, substantially on line 4-4 of Figure 3; and

Figure 5 is an enlarged, somewhat diagrammatic end elevational view of the digging elements showing the relative arrangement of adjacent elements.

My implement includes a support frame having a horizontal, rectangular base plate 10. Rigid with and projecting upwardly from opposite sides of base plate are side portions 12 of the frame, of inverted U-shape. Bearing plates 14 are secured to and project upwardly from base plate 10, receiving stub axles 16 on which ground wheels 18 are mounted. Obviously, the details of mounting of the ground wheels, and other details of frame construction, can be varied if desired and hence will not be described in full detail herein.

Parallel, flattened inner end portions 20 of elongated handle bars are pivotally connected at their ends as at 22 to the forward legs of the side portions 12 of the frame. Said forward legs have longitudinally spaced openings to locate the pivot axis of the handles wherever desired, according to the desires of a particular user. Rearwardly of the side portions, the parallel leading portions 20 of the handles merge into rearwardly diverging portions 26 which in turn merge into parallel rear end portions provided with hand grips 28.

A motor 30 is mounted upon the base plate, and can be an electric motor, an internal combustion engine, etc. An electric motor is illustrated merely by way of example and includes a cord 32 controlled by a switch 34 mounted .on one of the handles (see Figure 1).

Referring to Figure 3, in the illustrated example the shaft of the motor extends into a transmission gear case 36, and is secured within said case to a drive pinion 38 in meshwith a larger gear 40 also journalled within the case and secured to a shaft 42 that extends into a coupling sleeve 44. Also extending into the coupling sleeve is the rear end of an elongated drive shaft 46, set screws 48 or equivalent means being employed to connect the shafts 42, 46, and sleeve 44 for conjoint rotation.

Shaft 46 extends through a transversely elongated, upwardly opening gear housing 50 which may be streamlined or otherwise shaped, and which is equipped with a removable cover plate 52. Within housing 50 is a series of gears including a drive gear 54, gears 56, 58 at opposite sides of and meshing with the drive gear, and gears 60, 62 in mesh with the gears 56, 58. All the gears are mounted to rotate in a common vertical plane disposed transversely of the device, with the gear housing being mounted upon the front end of the support frame.

Secured to gears 56, 58 for rotation therewith are forwardly projecting shafts 64, 66 (Figures 1 and 4). Similarly secured to the gears 60, 62 are shafts 68, 70. The several shafts are journalled in the forward and rear walls of the gear housing, and it will be understood that the bearings of the shafts will be made suitably proof against the admission of dust or dirt into the gear housing, or the leakage of oil from the housing.

As will be noted from Figure 2, wherein a dotted line has been drawn, there is a particular relationship between the pointed forward end portions of the augers and the shafts of the angers, with said relationship including the ground wheels. If the dotted line in Figure 2 is considered as a plane, it will be noted that this plane is tangential to the ground wheels 18 at the point of contact between said wheels and the ground surface, said ground surface being illustrated as a horizontal broken line in Figure 2. With further reference to this dotted line in Figure 2, it is to be noted that it passes through the pointed tips of the forward angers 72. The forward portions of these angers are disposed in planes perpendicular to the plane represented by the dotted line in Figure 2.

Now, it will be noted that if the device is rocked counterclockwise in Figure 2, from its Figure 2 posi tion, to lower the augers into engagement with the ground surface, the plane represented by the inclined dotted line in Figure 2 moves into a horizontal position, that is, it moves to a position in which it is coplanar with the ground surface. At this time, said forward portions of the angers, since they lie in a plane perpendicular to the mentioned plane, will dig into the ground while being disposed substantially in planes perpendicular to the plane of the ground surface. The forward portions of the Patented Mar. 10, 1959 3. suga s th s re paused to t a el into the around in armate or circular paths, While in planes perpendicular to the plane of the ground surface and disposed broadside to the path :of movement of the-device as it .is pushed for.- uvardly along the ground. This provides a highly effec- .-tive digging .action.

In any event, the shafts .46, 6.8:, 70 alternate with the shafts .64, 66 and project beyond the forward ends of the shafts .64, 66 a short distance as shown in Figure 1. .Connected to the forward ends of the several shafts are .digging elements in the form of spirally extending blades or :augers which, asshown in Figure 5, have inner ends coaxial with theshafts, the angers .72 being formed at their .inner ends with threaded sockets threadedly en- :gaged with the forward ends of the shafts. The angers ;of the shafts 64, 66 rotate oppositely to the angers of the remaining shafts, as will be readily apparent by studying the meshing gears of Figure 4, and therefore the threads of the shafts ,64, 66 and of theirassociated auger sockets 74 are of one :hand, while the threads .of :theshafts 46 6.8, 70 are of an opposite hand.

As shown in Figure 5, each anger is extended ,Pi rally vfrornits inner end ina forward direction ,(see Figure l) with the vouter ends of the angers being beveled or pointed as at 76. The arcuate paths within which the outer ends of the angers travel overlap, sofar as adjacent, oppositely rotating angers are concerned (see Fig- ,ure 5,), thus .toinsure that noportion of the ground will the-left untouched by the angers during the operation of the device.

In use ofthe device, the shafts 46 are disposed at an angle of approximately twenty to twenty-five degrees to the ground level, although ,theextentof movement of the auger into the ground can ,be governed by increasing or reducing this angularity of the shaft to-the ground level, as desired. 9 In practice, it has been found that the implement is useable to considerable advantage in weeding, mulching, and working the :soil. The illustrated example of the invention is intended primarily for relatively small plots, such as the family garden and hence is relatively nar- .row, so that it may properly operate between adjacent rows of crops. However, the implement could be made in various sizes, depending-upon the work to be done and of course a larger size would require a somewhat larger gear housing with additional gears, shafts, and digging angers, and would also requirea larger prime mover.

In operation, the angers or :spirally shaped teeth revolve at high speed. Only a small bite is taken out of the ground by each auger'during each revolution thereof, so thatthe soilis moved or pulled only a relativelyshort distance. As a result, it has been found in practice that very little power is used in comparison with various other types of weeders, tillers, mnlchers, and cultivators, :fill .DfiWhlCh have to move .soil a greater distance, requiring a correspondingly increased amount of power.

Further, the spirally shaped angers or teeth have a tendency to pull the instrument forward, by digging into the ground, so that the implement is, so to speak, semiself-propel ed in tha he a er assist in f rward movement of the implement thereby relieving the operator of a considerable amount of this burden. At the same time, the implement is relatively light in weight, and handles and turns easily, so as to permit it to be readily used by a woman or child.

The adjustment of the implement for depth is effected simply by raising or lowering the handle bars during the forward movement of the implement and the operator can readily determine while the implement is in operation whether it is operating at a proper depth.

It has been found that the whirling motion of the teeth is effective in removing all the weeds and at the same time does a very thorough job of loosening and mulching the soil without throwing dirt.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construe; tion that may be permitted within the scope of the appended claim.

What isclaimed is:

A ground-working implement comprising: a support frame including abase plate; a pair of ground wheels supporting said base plate for rocking movement about the axis of the ground wheels; drive means mounted on the base plate to rock therewith; handle means-extending rearwardly from and having a fixed connection to the frame for rocking the frame; a plurality of transversely spaced shafts projecting forwardly from and driven by the drive means, said shafts, handle means, drive means, and frame being connected to form a unitary assembly all components of which are linked for conjoint rocking movement about the ground wheel axis only; and a plurality of digging angers rigid with the several shafts for rotation thereby, said angers each being formed as a spiralling red the convolutions of which spiral forwardly from their associated shafts while curving about the cen: ters of the shafts, the angers having pointed forward end portions, extending in planes approximately perpendicular to a plane that is tangential tothe ground wheels at the point of contact between the ground Wheels and the ground surface and that passes through the pointed forward extremities of some, at least, of the angers.

References Cited in the file of this patent UNITED STATES PATENTS 1,184,276 Townsend May 23, 1916 1,223,029 Butler Apr. 17, 1917 2,490,870 Heyn Dec. 13, 1949 2,574,353 Singer Nov. 6, 1 951 2,622,498 Wharton Dec. 23, 1952 FOREIGN PATENTS 85,173 Switzerland May 17, 1920 

